The Schelde estuary, characterised as a turbid, polluted and very eutrofic system, has nowadays reached a turning point in the restoration of its water quality. During the past century, human activities have reduced the intertidal areas, essential in the estuarine ecosystem for nutrient cycling and the self-cleaning capacity. Today, in combination with a master plan to protect the population from storm surges, an opportunity rises to recreate areas with a tidal influence. One specific option of combining safety and ecology is the creation of controlled inundation areas (CIA) under influence of a controlled reduced tide (CRT). These specific areas will differ in many ways from fully tidal areas. However, these areas can fulfil important ecological functions. The ecological development of a CRT will be investigated in the 10 ha big study area Lippenbroek. This former polder area will be turned into a small CIA-CRT to test this new concept.